How do you simplify  12 sqrt (1/3) - sqrt27?

I found: $\sqrt{3}$
$\sqrt{\frac{{12}^{2}}{3}} - \sqrt{3 \cdot 9} = \sqrt{4 \cdot 12} - 3 \sqrt{3} = 2 \sqrt{12} - 3 \sqrt{3} =$
$= 2 \sqrt{4 \cdot 3} - 3 \sqrt{3} = 4 \sqrt{3} - 3 \sqrt{3} = \sqrt{3}$